I am working on a model to optimize a fleet of over 450 school buses and what trips they will service. Everything works beautifully, except one thing, and I will describe the scenario.
When the school bell rings in the afternoon at 2:00 PM the bus should be there and wait 7 minutes to service the order (servicetime). The bus should depart at 2:07 PM ideally. However, if I strictly enforce this time rule, I am left with an unrealistic increase in equipment because I some buses will be late. However, If I allow buses to be late say 5 minutes, then a bus can arrive at 2:05 PM, but since my service time always remains 7 minutes, I am left with is a bus leaving at 2:12 PM, which distorts my next set of orders. What I need is a way to subtract service time from arrival time, but is there a way I can set service time dynamically?
Here's what ESRI says:
A time window only states when a vehicle can arrive at an order; it doesn't state when the service time must be completed. To account for service time and leave before the time window is over, subtract ServiceTime from the TimeWindowEnd1 field.
What they fail to say is where and how to do this. Any suggestions?